Question

Calculate the moles of Cu in 7.4×1021 atoms of Cu.

Answer 1

1 moles -------- 6.02x10²³ atoms
 ?? moles ----- 7.4x10²¹ atoms

moles = 7.4x10²¹ / 6.02x10²³

 = 0.01229 moles

hope this helps!